Demand regulator



June 13, 1961 H. A. BENZEL DEMAND REGULATOR Filed May 7, 1956 5,? 22 l23 l I I I I 29 In. IM

INVENTOR.

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United States Patent F 2,988,097 DEMAND REGULATOR Howard A. Benzel,Lancaster, N.Y., assignor to Scott Aviation Corporation, Lancaster,N.Y., a corporation of New York Filed May 7, 1956, Ser. No. 583,034 2Claims. (Cl. 137-63) This invention relates to a regulator forautomatically supplying artificial breathing fluid to a person wheneverhe inhales, and in whatever amount he desires, i.e., it suppliesbreathing fluid on demand and at whatever volume of flow is demanded byhim.

The main object of the invention is to provide a demand regulator whichdoes not have to be cracked open, i.e., which provides a flow ofbreathing fluid the moment the inhalation pressure drops a very slightamount below the ambient pressure. Other collaterial objects of theinvention and practical solutions thereof are explained in the followingspecification and illustrated in the accomp anying drawing, wherein:

FIG. 1 is a vertical, longitudinal section thru the demand regulatorshowing the butterfly demand valve 30 in its closed position.

FIG. 2 is a similar, vertical, longitudinal section thru the demandregulator but showing the butterfly demand valve 30 in its fully openedposition.

FIG. 3 is a vertical, transverse section thru the demand regulator,taken in line 33 FIG. 2.

FIG. 4 is a fragmentary, vertical, longitudinal section showing theexterior of the butterfly demand valve 30, taken on line 4-4 FIG. 3.

For the sake of brevity this invention will be described precisely as itis illustrated, but it is to be understood that the scope of theinvention is to be measured solely by the breadth of the appended claimsand by the intrinsic novelty or spirit of the invention.

The casing 5 of the demand regulator here illustrated consists of a maincasing body 6 and a cover 7, both of which are of cylindrical shapearranged on a horizontal, longitudinal axis. Compressed air (or otherbreathing fluid) is supplied to the demand regulator thru a pipe nipple8, the latter being connected to a supply of compressed air, such as acompressed air tank, not shown. Air from a breathing compartment 10leaves the demand regulator thru an outlet duct 11 from whence it passeseither to a breathing mask (not shown) or directly into the mouth of thewearer.

Arranged between the cover 7 and the main casing body 6 is a pressuresensitive member which, as illustrated, is a flexible diaphragm 12 towhich is molded a sheet-metal backing plate 13 that is annularlyperforated adjacent its periphery by a series of holes 14 thru which thematerial of the diaphragm 12 passes during the molding process, therebyfirmly securing said backing plate 13 to said diaphragm 12.

The cover 7 is perforated at 15 so that the outer face of the diaphragm12 is exposed to ambient pressure, while its inner face is exposed towhatever pressure exists in the breathing compartment 10. Secured to thecentral part of the backing plate is a horizontal, longitudinal,inwardly extending stud 16 which is pivoted at 17 to the outer end of alink 18. The latter is pivoted at 20 to the upper, bifurcated end of anupstanding 2,988,097 Patented June 13, 196 1 post 21 which is secured tothe central part of a horizontal, transverse, cross yoke 22 by a studscrew 23 which is shouldered against the lower substantially horizontalface of the yoke 22.

Secured to the lower part of the main casing body 6 by a clamp nut 24 isa vertical, tubular, balanced-valve housing 25 whose upper end is openand whose lower end is threadedly, tubularly connected to aforesaid pipenipple 8. The outer ends of the cross yoke 22 are integrally providedwith a pair of depending legs 26 and 27 which are pivotally connectedwith the exterior of the valve housing 25 by a pair of pivot screws 28,29 that are firmly held in their adjusted position by a suitable pair oflock nuts.

Formed integrally at the lower, distal end of the stud screw 23 is adisk-shaped, balanced, demand valve or butterfly valve 30 whose medial,horizontal, transverse diameter is axially in line with the common axisof the pivot screws 28, 29, so that as the cross yoke 22 is swung aboutthe axis of said pivots, the butterfly valve 30 is correspondingly swungabout its medial, horizontal, transverse diameter.

Inasmuch as this butterfly valve 30 is here being employed as a demandvalve in a demand regulator, it is essential that it make an absolutelytight seal, when closed, with the bore of the cylindrical valve housing25. To obtain this fluid tightness of said butterfly valve an annulargroove is machined in the central part of its periphery and in thisgroove is arranged an O-ring 31 which may be composed of either sometype of rubber or of other plastic material. It should be understood,however, that this matter of fluid tightness has nothing to do with thefact that the butterfly valve 30 is a balanced valve, i.e., any changeof pressure on either of its faces, or any diflerential of pressures onits two opposite faces, does not tend to cause any rotation of saidbutterfly valve 30. It is inherently a balanced valve, and hence doesnot have to be cracked open like an ordinary demand valve but, instead,starts to open immediately when the pressure in breathing chamber 10drops slightly below the ambient pressure in cover 7.

It is desirable that the fully closed position of the butterfly valve 30be definitely limited relatively to the demand valve housing 25 ratherthan relatively to the easing 5 because in the latter case the additionof tolerances might result in improper seating of the butterfly valve.For this reason a stop 32 is formed on valve housing 25, said stop beingadapted to take the thrust of the outer face of the yoke 22 when thebutterfly valve is in completely closed position.

Said butterfly valve 30 is resiliently urged toward its closed positionby a spiral spring 33 (see FIGS. 4 and 3) which is coiled around thelock nut of the pivot screw 28 and has its opposite ends received in asuitable hole drilled horizontally in the leg 26 of yoke 22 and in asuitable hole drilled horizontally in the butterfly valve housing 25.

I claim:

1. A demand regulator comprising: a casing having a breathingcompartment; a pressure-sensitive member arranged in said casing andexposed on its one face to the pressure within said breathingcompartment and exposed on its other face to the ambient atmosphere orother ambient medium; an open-ended, tubular housing connected with saidcasing and opening into the breathing compartment thereof; a balancedvalve arranged within said housing but pivotally connected with theexterior thereof and adapted to discharge breathing fluid into saidbreathing compartment and operatively connected with saidpressure-sensitive member; and means for supplying breathing fluid underpressure to said balanced valve.

2. A demand regulator as in claim 1 with the balanced valve being abutterfly valve which is secured to a yoke which is pivotally connectedto the housing extei'iorly thereof.

References Cited in the file of this patent UNITED STATES PATENTSHarwood Sept. 25, Seeler Jan. 8, Meidenbauer Dec. 27, Ray Oct. 15,

FOREIGN PATENTS Great Britain Oct. 4, Great Britain July 8, Germany Mar.30,

